Integrating Decision Elements for Behavioral Switching

成功的动物倾向于在日常活动中做出有效的决定，包括付出的努力、承担的风险和获得的利益。相反，影响健康的糟糕决定是焦虑、抑郁和许多导致行为障碍的精神疾病的特征。因此，掌握决策的神经基础对于任何统一的框架都是必不可少的，这些框架可以模拟大脑正常和异常行为的组织。对决策的神经基础至关重要的是对神经系统如何整合感觉、内部状态和学习的描述。通过对浅海蛞蝓（Pleurobranchaea）行为和神经系统的研究，推导出一种简单的觅食成本-收益决策神经网络模型。在该模型的背景下，进食运动网络被认为是一个“目标导向的神经网络”，其兴奋状态由感觉、营养状态和学习调节。这种特性赋予了组织行为表达的成本-收益算法的核心计算元素的作用。本文概述了食欲刺激特性、饱足状态和食物回避学习如何通过进食运动网络影响定向转向和回避转向的运动网络决策的基本原理和实验计划。具体来说，研究将旨在解释定向和回避转换的神经基础，这种转换是如何由感觉、食欲和学习决定的，以及回避决策如何抑制摄食行为。研究将在经过充分测试的生理制剂上使用传统的电生理记录方法进行。研究结果将具有广泛的综合意义，有助于理解动物如何在对可用资源和风险的感知与自身需求之间取得平衡，从而做出成功的行为决策，并为研究更复杂动物中类似基于价值的决策的神经回路提供一个简单的模型。本科生，包括少数民族成员，都参与了这些实验室研究活动。本实验室的相关研究资料，包括视频、照片和软件，在一个专为本科生和外行编写的网站上发布，供公众了解海蛞蝓行为的神经基础。

Successful animals tend to make efficient decisions in their daily activities in terms of effort spent, risk taken and benefit gained. In contrast, poor decisions affecting fitness are characteristic of anxiety, depression and many forms of mental illness that contribute to behavioral dysfunction. A grasp of the neural bases of decision is therefore essential to any unifying framework that models the organization of normal and abnormal behavior by the brain. Critical to the neural bases of decision is a description of how the nervous system integrates sensation, internal state and learning. A simple neural network model has been derived for cost-benefit decision-making in foraging from studies of behavior and nervous system in the simple predatory sea-slug, Pleurobranchaea. Within the context of the model, the feeding motor network is usefully conceived as a "goal-directed neural network" whose state of excitation is regulated by sensation, nutritional state and learning. This quality confers a role as a central, computational element for the cost-benefit algorithm that organizes expression of behavior. Rationale and experimental plans are outlined to elucidate how appetant stimulus properties, satiated state and food-avoidance learning act through the feeding motor network to influence decision in the motor network mediating both orienting and avoidance turns. Specifically, investigations will be aimed at explaining the neural bases for switching between orienting and avoidance turns, how this switch is determined by sensation, appetite and learning, and how avoidance decision may suppress feeding behavior. Studies will be carried out with conventional electrophysiological recording methods on well-tested physiological preparations. Results will have broad integrative significance to understanding how animals make successful behavioral decisions that balance perception of available resources and risk against their own needs, and will provide a simple model for approaching the neural circuitry for similar value-based decision-making in more complex animals. Undergraduate students, including minority members, are involved in these laboratory research activities. Research related materials from this lab, including videos, photographs and software, are disseminated for public information on the neural basis bases of behavior in sea slugs on a website written for accessibility by undergraduates and laypersons.